Annual Vinca not looking so good

We planted vinca (the annual) here in SE MI this year and so far it is not looking good. It was reported to be very drought dolerant etc.etc..

We have had lots of rain here in Detroit over the past 2 weeks and I fertilized these flowers with a Miracle-Gro sprayer this past week. Well, some are wilting and some leaves have turned yellow. I sprayed them down with water to wash off any Miracle-Gro in case this was a problem.

Any ideas? They get plenty of water due to the rain and we have a dripline matrix in this bed. (no, we didn't run the drip with all this rain)

VINCA DOES NOT LIKE WATER! A technology park we maintain always insisted we plant Vinca because it was suggested by the designer... drought tolerant, low maint. etc. It never thrived however because they overwatered. Once its established average rainfall should be more than enough water to sustain it. Vinca is a SUN HOT loving annual, if planted too early it will not thrive.
We FINALLY convinced them to let us plant Wave Petunias and the customers are raving! They said park has never looked better! I think the key to success is matching the annual to the site. Good Luck with the Vinca.

A good rule of thumb is- if it is drought tolerant then it won't tolerate wet feet, heavy soils. Junipers and many other drought tolerant plants are the same way, they don't tolerate wet feet.

Cheak the soil composition and choose from a list of annuals that suit the soil, light and ph conditions.

It sounds like disease crown rot, root rot it may also be salt burn from the miracle grow. Many plants, especially drought tolerant ones, can absorb fertilizer too fast and the result is the sort of discoloration you discribed. Roses are famous for salt burn from high N fertilizer. This often results in the death of the plant.

Thanks guys, I cut way back on the irrigation and am hoping for the heat of summer to finally arrive, tho that isn't looking promising for at least a week. Hopefully they will get through this wet spell and improve once the heat hits.

A good rule of the thumb is to not plant vinca where there is irrigation. Vinca is jokingly referred to as a good residential mailbox plant because most homeowners' hoses don't reach that far! Too much water and cool temperatures will cause brown root rot in a hurry. It does best when planted late in very hot, well drained beds. Once you get root rot disease in those beds it is difficult to get rid of and will sometimes transfer over to your pansies in the fall. I personally like the look of vinca but it is too much trouble and not reliable enough. With the huge selection of summer annuals I would look for a better plant than vinca.